1. Technical Field
The present invention relates to cloth cutters and, more particularly, to resealing mechanisms for resealing the cuts made by the cutter during cutting operations to minimize vacuum loss.
2. Background Art
Conventional cloth cutter systems include a cutter table and a cutter head movable with respect to the cutter table in a longitudinal direction and guided by a pair of rails disposed along the cutter table. The cutter table supports a single ply or multiple plies of cloth material, referred to as a lay. The cutter table extends from Typically, the cutter table includes an air permeable support surface to allow vacuum air to pass therethrough. The vacuum draws the lay against the cutter table support surface to prevent displacement of the lay during the cutting operations and to compress the lay during the cutting operations. In order to achieve and maintain the vacuum during the cutting operations, a layer of air impermeable overlay material is placed atop of the lay prior to the onset of the cutting operations. Typically, the overlay material is a thin plastic film that can be easily cut by the cutter tool.
During the cutting operation, the overlay material is held in place by vacuum. However, as the cutter tool cuts the lay into parts, the overlay material is also cut. Once the overlay material is cut, the air can permeate through the cuts and causes loss of vacuum. The resulting loss of vacuum during the cutting operations is highly undesirable because the plies of material are no longer compressed or held in place, resulting in inaccurate subsequent cuts.
Existing cutter systems include a resealer mechanism to seal the cuts and thereby conserve vacuum. One such resealer is described in a U.S. Pat. No. 5,289,748 to Kuchta et al. and assigned to a common assignee with the present invention. Conventional resealer mechanisms include a first roll with resealer material attached to one end of the cutter table and a second roll with resealer material that moves with the cutter head. These resealer mechanisms typically include a pair of rigid brackets that support the second roll with resealer material. The brackets attach to the end castings of the cutter head such that the second resealer roll travels in the longitudinal direction with a cutter head. The second roll with the resealer material must be positioned sufficiently far above the cutter table support surface to accommodate lays of maximum height.
However, many cutting operations involve cutting smaller lays. Therefore, for those cutting operations, the gap between the second resealer roll and the top of the lay is large, resulting in vacuum loss. Because a large gap is formed between the second resealer roll and the top of the lay, the vacuum that passes through the cuts cannot overcome the rewinding force of the resealer roll and cannot immediately draw the resealer material coming off the resealer roll toward the lay to reseal the cuts. This results in an area of cut lay that is not immediately resealed.
Additionally, the geometry of the cutter head interferes with the second resealer roll and therefore prevents the second resealer roll from being in close proximity to the cutter tool. Thus, the resealer roll is positioned away from the tool, resulting in vacuum losses. Furthermore, the problem is exacerbated by newer, wider cutters. In the wider cutters, a greater total area of the cut lay is exposed, and therefore more vacuum air can escape through the cuts.
It is an object of the present invention to improve cutter systems.
It is the another object of the present invention to provide a resealer mechanism that minimizes vacuum loss during cutting operations.